The present invention relates to optical gratings, and more specifically, to embedded vertical optical gratings in heterogeneous integration.
To further improve the performance of computational systems, it is desired to integrate optoelectronic devices and Micro-Electro-Mechanical Systems (MEMS) with Complementary metal-oxide-semiconductor (CMOS) devices into a micro-system. With three-dimensional integration (3DI) becoming a technology offering, it become becomes feasible to achieve the heterogeneous integrated micro-system.
In optoelectronics, one useful component is an optical grating. Gratings are optical devices used to achieve wavelength-dependent characteristics by means of optical interference effects. Optical gratings are used to achieve filtering, coupling, or mode transforming functions for the optoelectronics. Currently, semiconductor gratings are typically implemented on surface of a substrate by etching a grating pattern into the surface of the semiconductor guide (which may then be buried following subsequent deposition) to have a periodic change of reflective index.